Apparatus for forging five-point rock-drill bits



Dec. 4 1923. 1,475,939

J. DITSON APPARATUS FOR FORGING FIVE-POINT ROCK DRILL BITS Filed June 50. 1922 2 Sheets-Sheet 1 INVENTOR Dec. '4 1923. 1,475,939

J. DITSON APPARATUS FOR FORGING FIVE-POINT ROCK DRILL BITS Filed June 30. l922 2 Sheets-Sheet Z HID ATTOR Y Fatehted Dec. 4, 1923.

UNITED STATES 5939 PATENT oFFicE.

{JESSE DITSON, OF LITTLETON, COLORADO, ASSIGNOR TO INGERSOLL-RAND COMPANY,

\ OF JERSEY CITY, NEW JERSEY, A CORPORATION ,OF NEW JERSEY.

APPARATUS FOR FORGING FIVE-POINT ROCK-DRILL BITS.

Application filed June 30, 1922. Serial No. 571,942.

stance, as working in coal, it has been found very difficult to form such bits in anyof the standard drill sharpening or forging machines which have supplanted hand-sharpening in every important connection.

Essentiallygthe five point bit of the type which has been found very satisfactory for working in coal consists of alarge head having five radial wings of considerable length terminating in cutting edges. The head may either be formed in such manner as to be attached to the forward end of a drill steel, or may be integral with the drill steel, which may be either solid or hollow.

The outer sides of the bit conform generally to the contour of a cone, and the sides of the wings are preferably flat and taper towards the cutting edge and are given a greater degree of taper near the cutting edge. The center of the cutting face of the bit is formed into a conoidal recess, which may terminate at the hollow bore extending 7 through the shank of the drill steel when a hollow steel is used, and this conoidal recess separates the forward ends of the wings, leaving five radial chisel edges.

' Since it is an important feature of this type of bit that the radial wings which terminate in the cuttinguedges shall extend back to the base of the enlarged diameter portion of the drill steel constituting the bit end so as to permit the bit to cut deeply and allow adequate passage for the cuttings, it

is necessary in forming such drill bits with the required backwardly tapering sides and inclined surfaces that the angles of inclination and' convergence of the several surfaces and sides of the respective radial cutting member shall be properly formed on the bit in order to produce a structure which will accomplish the best results in practice.

The proper forming of five point bits has heretofore proven a tedious and difficult task, as a result of which such bits, which possess great advantages for certain purposes, have not been as generally used as other types of bits less eflicient for such purposes.

The primary object of this invention is to enable five point drill bits to be forged or mechanically formed by an apparatus which will permit a drill sharpening machine such as shown in my Patent No. 1,258,998 dated March 12, 1918, to be used in conjunction with a standard set of dies, so thatthe five point bits may be manufactured by a series of upsetting and swaging operations performed in and by a drill sharpening or similar machine equipped with such standard set of dies, the manufacturev of such bits being thereby greatly simplified.

Further objects will later appear and to the ends set forth the invention consists in the features of constructiton and operation set forth in the following specification and illustrated in the accompanying drawings, in which- Figure 1 is a vertical sectional view through a portion of a drill sharpening apparatus embodying the invention, illustrat mg, specifically, the upsetting or dollying' operation;

Figure 2 is a side view of a partially formed drill bit as it appears after the upsetting operation; Y

Figure 3 is an end view of the partially formed bit illustrated in Figure 2;

Figure 4 is a side view of a finished bit;

' Figure 5 is an end view of the finished bit shown in Figure 4;

Figure 6 is a vertical sectional View of the partially formed drill bit and lower swaging die in'position for carrying out the first step in the swaging operation;

Figure 7 is a view partly in section taken on the line 7-7 of Figure 6, looking in the direction of the arrows, showing the upper and lower swaging dies and the partially formed drill bit in the same position as in Figure 6;

Figure 8 is a verticalsectional view of the lower swaging diewith the drill steel in pooperation subsequent to, the step illustrate in Figures Gand 7; t 7

Figure 9 is a sectional view of the drill bit taken on the line 99 of Figure 8, looking in the direction of the arrows;

Figure 10 is a vertical sectional view of the lower swaging die with the drill steel in position for carrying out a step in the swaging operation subsequent to the step illustrated in Figure 8;

Figure 11 is a sectional view of the drill bit taken on the line 11-11 of Figure 10, looking in the direction of the arrows;

Figure 12 is a vertical sectional view of the lower swaging die with the drill steel in position for carrying out the final step in the swaging operation; and

Figure 13 is a sectional view of the finished drill bit taken on the line 1313 of Figure 12 looking in the direction of the arrows.

The process is usually carried out in a drill forming and sharpening machine such as shown in my prior patent before mentioned, only the essential forming parts being here illustrated. The drill forming and sharpening machine comprises a stationary anvil block or jaw A and a movabl block or jaw B. Secured in one side of the anvil block A and of the block B are a pair of opposite upper and lower forming or upsetting dies C and D, in the inner faces of'which are longitudinal semicylindrical grooves or depressions E and F, respectively, together forming a cylindrical bore for holding the shank of a heated drill steel G, these semi-cylindrical depressions E and F diverging near the outerfaces of the dies C and D to form semi-conical recesses having inclined cooperating shaping faces H and J, which together form a true conical aperture when the anvil block A and block B are closed upon a drill steel, as shown in Figure 1.

- riveted.

Coacting with the upsetting dies C and D and adapted to enter the recess between the dies C and D is an upsetting or forming dolly K, mounted in the cylinder L of the percussive element forming a part of the drill sharpening machine. The. dolly K is adapted to be actuated by blows administered on. one end of the cylindrical shank O by a member P, only partly shown here: in, which ma be a reciprocating piston or, an anvil block actuated by a reciprocating piston'or any similar device.

The opposite end Q of the dolly shank is formed into a tapering end or point R, and a hollow five point annular former head S is adapted to fit around the pointed end B, being secured on the shank Q, by one or more pins T, the ends of which may be The head S abuts against a shoulder U at the end of the shank portion Q opposite to the oint R, and the wall of the interior bore of the head 8 at the end adjacent to the point B forms a conical recess W, the taper of the walls of which corresponds to that of the point R, so that there is a close fit between the head S and shank Q. The head S is thus firmly secured and braced on the shank Q at the points W,

U and T.

The former head S is provided with a plurality of circumferentially disposed V- shaped depressions or grooves X, in the present instance five, and tapered angular formers or points Y alternating with said grooves. The formers Y are disposed diametrically around the pointer R at an angle of 72 from each other, and have sharp inwardly inclined forming edges Z.

The outer sides a of theformers Y are inclined in the same degree as the tapered conical aperture in the die blocks C and D.

In the operation of the apparatus so far described the shank of the heated drill steel G is inserted in the grooves E and F of the dies C and D and the upper clamping jaw or block B is brought down on the stationary jaw or anvil block A, so that the shank of the steel is clamped firmly between the dies,

C and D, its outer endprojecting into the conical aperture formed by the conical grooves H and J and, if necessary, beyond the same a distance depending on the gauge of the bit to be formed. The steel G may project approximately to the end of the pointer R, this pointer B being in axial alignment with the longitudinal bore 6 of v the hollow drill steel G, since a hollow steel is shown in this instance, and the size or length of the forming dolly, and hence the distance of the dolly operating face from the ends of the dies C and D may be so calculated that this distance will equal the distance which the drill steel G should properly project beyond the dies C and D in order to provide the necessary amount of metal required for upsetting the steel and forming a drill bit of the specified width or gauge for which the particular dolly is adapted.

The dolly K is then actuated in the manner outlined above which is well understood, to upset the end of the drill steel Gr. The formers Y and pointer R, which together constitute the operating'face ofthe dolly, and the cooperating conical apertures H and J in the dies C and D, cause the upset end of the steel to assume a corresponding external conformation.

The product of the operation just set forth is a drill shank with a partially formed bit. consists of ,an enlarged symmetrical end a of a diameter approximately equal to the gauge finally desired and five distinct symmetrical tapering portions 0! having radially disposed straight parallel cutting edges or surfaces e, these tapering portions (i being disposed around a central The partially formed bitthe inwardly directed conoidal depression 7, which terminates in the bore 6 of the hollow drill steel. Between the portions d are angular depressions g. .The portions d have rounded inner and outer surfaces d and d respectively, and flat inclined opposite converging sides cl these flat. sides d constituting the walls of the angular depressions g and forming the straight cutting edges 6 at the outer point of convergence of the sides d of each portion (1. The'rounded inner faces d of the portions (1 constitute the wall of the conoidal depression f.

The next step in the operation of forming the five point bit is carried out in a pair of swaging dies which are adapted to be placed in the jaws A and B of the drill sharpener in the same manner as the dies 0 and D. These swaging dies include an upper swaging die It and a cooperating lower swaging die j. The upper swaging die it has a central vertical longitudinal depression or groove is in its under side, this groove 1: being formed by opposite plane outwardly converging side forming surfaces 0 and a rearwardly and inwardly inclined top or end 2. Opposite separate forming surfaces 9 and r, one at each side of the central groove is and inclined upwardly at an angle of approximately 72 to the vertical axis of the central groove is, form the base or operating faces of the upper die It.

The lower die 9' has two depressions or grooves t and u in its: upper side. These grooves t and u are disposed at an angle of 72 to each other, the point of convergence ofthe Vertical axes of the grooves t and u being in alignment wit-h the vertical axis of epressionor groove [0 in the upper jaw h. The grooves t and uhave side and end surfaces 0 and 79, respectively, corresponding in all respects to the side and end surfaces 0 and p of the groove in the upper die it. The outer surfaces 4; and 20 adjacent to the longitudinal sides a: of the lower die j are inclined abruptly outwardly and upwardly beginning at the shoulders 2 which are located in the same distance from a hypothetical point 3 (representing the point of convergence of the vertical axes of the grooves t and u and the groove k of the lower and upper dies 7' and k), as the shoulder 2' which is located at the pointof convergence of the two inner surfaces 0 of the grooves 25 and u, so that separate inclined fiat forming surfaces 0 and w are formed. These surfaces 0 and 'w are opposite to the surfacesq and 1', and their angle of inclination with respect to the vertical axes \of the two grooves 23 and u in the lower swaging die j corresponds with the angle of inclination of the surfaces 9 and r in the upper die It with respect to the vertical axis of the groo 'e k.

Together, the diesh and 7' having the opposing surfaces 9 and 'v and r and 'w constitute opposite shaping and forming members. When the dies h and j are caused to approach each other, the heated drill steel being between the dies, the surfaces g, o, 1' and w in effect correspond approximately to the sides ,0 of the depressions k and 1). Such correspondence will be exact, when the forming surfaces 9 and 1- are the same distance from the surfaces 2: and was the sides 0 of the depressions la and p are from each other. Because of the fact that the vertical axes of the grooves in and p, as well as the vertical axes of the spaces between the surfaces 9 and o, and r and w, respectively, all radiate from the same point 3 when the jaws h and j are in the position for exact correspondence referred to, and because of the further fact that all the surfaces are symmetrically disposed, and number five or multiples thereof, each of the depressions and surfaces will be at an angle of 72 to its adjacent forming surface ordepression.

tially formed in the forming dies C and D as shown in Figures 2 and 3, is placed between the dies k and j at a point some distance from the outer end of the dies h and j, as shown in Flgures 6 and 7. The dies h and j may be mounted in a different location on the drill sharpener than the dies C and D, but are secured to thestationary' and movable members A and B. When the partially formed bit has been placed between the dies h and j twoimmediately adjacent portions (Z find lodgement in the grooves t and u, of the lower swaging die: 7', and the portion (1 opposite these adjacent portions is aligned with the groove is of the upper die. The remaining opposite por tions d are located between the surfaces I1 and '0 at one side, and the surfaces 1' and w at the other side. The upper swaging die It is then moved up and brought down forciblyupon the heated steel a few times with the steel in the position shown in Figure 6, the steel being rotated or turned each' time so that opposite portions d are successively positioned between the surfaces q and v, and r and w, to receive the blows and pressure administered by the upper die it. The" operation of the upper die it results in -the reduction of the angles of inclinationiand divergence of the flat sides d of each of the portions (1, commencing at a point short of the cutting edge, as shown in Figure 6,

which point is at some distance from the i i is actuated and the drill steel turned as in the first step of the swaging operation.

\ The vproduct of the second step as shown in Figure 9 differs from the partially formed bit shown in Figures 2 and 3 in that theportions d now possess more definition, the inclined surfaces (i having been formed into opposite inclined sides d. This step may be repeated any desired number of times, the drill being moved slightly further into the dies h and j each time. The angle of inclination of the surfaces q, '0, 1' and w is such that the width of the portions d is nounced, and the sides d attain greaterradial length and less width, as seen in Fi ure 11.

nother result which takes place as the drill steel is progressively moved into the dies is that the angular depressions bet-ween each of the portions (1 are lengthened simultaneously with the forming of the sides 03 and the beveled surfaces 0?. at each ste in the operations.

After the drill bit has een moved so far into the dies 71, and j that the point of convergence of the flat outwardly inclined opposite converging sides indicated at a under the swaging pressure of the dies h and j reaches approximately the point of juncture 0 of the enlarged diameter bit portion 0 with the shank of the hollow drill steel G, as shown in Figure 12 and indicated by the arrows in Figure 4, the bit will have assumed the conformation indicated in section in Figure 13, the sides (1* of each portion (1 being formed down quite thin in the shape of inclined elongated 'radial wings, the grooves 9 having been extended the greater distance indicated by the arrows between the two dotted lines in Figure 4 as compared with the distance indicated by the arrows between the two dotted lines in Figure 2 showing the partially formed bit roduced in the upsetting operation. The bit is finally completed as shown in Figures 4 and 5.

One important advantage of the present method and apparatus lies in the fact that only a single pair of upsetting dies C and D and a single pair of forming or swaging dies h and j are needed to form and swage down five point bits to the'proper gauge, the several operations necessary to properly swage' down this peculiar ty of drill bit after the preliminary upsettlng operation, all being performed by simply changing the position of the bit in the dies h and j inand one of said swaging dies having a central vertically disposed longitudinal groove with flat sides and a rearwardly inclined end, separate forming surfaces on opposite sides of sa d centrally disposed groove, said separate surfaces being inclined at an acute angle to the vertical axis of said central groove, the other swaging die having two grooves disposed at an angle to each other, said grooves having sides and ends corresponding to the sides and end of the groove in the first mentioned swaging die, separate forming surfaces in the second mentioned die disposed at a similar angle to the vertical axes of the respective adjacent grooves, said first named and said last named opposing separate forming surfaces being oppositely inclined and adapted to act on opposite sides of a drill steel.

2. Apparatus for forming a five point rock drill bit comprising, in combination with a drill sharpener, removable upper and lower swaging dies, one die being movable to and from the other to effect the swaging and one of said swaging dies having a central vertically disposed longitudinal groove with flat diverging sides and a rearwardly and inwardly inclined end, a pair of separate forming surfaces one on each side of said centrally disposed groove, said separate forming surfaces being inclined at an angle of 72 to the vertical axis of said central groove, the other swaging die having two grooves disposed at an angle of72 to each other, said grooves having sides and ends corresponding to the sides and end of the groove in the first mentioned swaging die, the point of convergence of the vertical axes of said two grooves being in alignment with the vertical axis of the groove in the upper jaw, a pair of separate forming surfaces in said second mentioned die disposed at a similar angle to the vertical axes of the respective adjacent grooves, said first named and said last named opposing pairs of separate forming surfaces being inclined rearwardly and inwardly at approximately the same angle as the sides and ends of the rooves in the dies, eachof said grooves an forming faces being at an angle of 72 to'its adjacent forming face or groove, said swaging dies being adapted to act on opposite sides of a drill steel.

3. Apparatus for forming rock drill bit, comprising, in combination with a drill sharpener, a pair of swaging dies, one die being movable to and from the a five point other to effect the swa ing and one of said said first mentioned groove and bein adaptdies having a central vertically disposed ed to receive two wlngs of said drlll steel, longitudinal groove ada ted to receive one and. a pair of separate inclined forming wing of a drill steel, and a pair of separate surfaces in the other die disposed at a simi- 1 6 inclined forming surfaces one on each side lar angle to the vertical axes of the respecof said centrally disposed groove, said sepative ad acent grooves, said opposing separate rate forming surfaces being inclined at an forming surfaces bein adapted to receive angle of 72to the axis of said longitudinal the remaining Wings 0% said drill steel.

groove, the other of said dies having two In testim'ony whereof I have signed this 2 4 10 grooves disposed at an angle of 72 to each specification.

other, said two grooves corresponding with JESSE DITSON. 

